What was found
CUSTOMER COMPLAINED OF INTERMITTENT ROUGHNESS. REMOVAL OF CYLINDERS REVEALED STICKING INTAKE VALVES. GUIDE TO VALVE TOLERANCE TOO TIGHT, BELOW MFG MINIMUM LIMITS. MFG CLAIMS TOLERANCE TOO TIGHT FROM NORMAL OPERATION. NO BUILD UP NOTED OF ANY KIND ON VALVE STEM OR INSIDE DIAMETER OF VALVE GUIDE. TOLERANCE WAS INCORRECTLY MACHINED AT PART/CYLINDER MANUFACTURE OR ASSEMBLY. RECOMMEND DISASSEMBLY AND INSPECTION OF NEW CYLINDER ASSEMBLIES TO CHECK TOLERANCES.